Developing Research question

Comparing Energy Sources

In the current age, the use of fossil fuels is falling under increasing levels of scrutiny both due to dwindling supply and looming "net zero" deadlines. While nuclear energy is certainly a possible source of renewable energy in the future, the claim that "In the future, nuclear energy is the best possible energy source for Australia" seems to be an opinion of many in the space, and warrants investigation. By comparing nuclear energy options to the best options that are currently implemented, a comparison can be made.

Other energy sources currently implemented, such as hydroelectric energy, do not directly compete with Nuclear energy. Biomass in particular is limited in growth by the rate of biomass waste generated by industry (EIA, 2024). Therefore the scope of comparison is limited to the most abundant and fast growing energy sources that directly compete with nuclear.

Table 1: Current share and growth of select energy sources in respect to total renewable share (Australian Government, 2023).

Solar PV demonstrates the second highest share in electricity generation, and is currently the fastest growing renewable energy. Therefore it will be the basis of this comparison.

Defining categories of comparison

Cost

Energy generation requires investment at many stages during a piece of infrastructures life cycle. Contributors to cost will be discussed. The cost per unit of energy produced should be considered as cost of living is a major issue in some parts of Australia (Potts, 2024).

Reliability

Critical sectors like healthcare and agriculture rely heavily on the grid, in addition to the millions of Australians who have improved quality of life because of it. If one technology demonstrates a increased reliability, this is a significant advantage.

Scalability

Looking towards the future, the waste product of each technology must be considered. These will accumulate during generation, and at the End Of Life (EOL) period of a piece of infrastructures lifespan. If one technology shows significant advantages and becomes the dominant power generation infrastructure, the long term impact of it's materials and processes must be considered, just as they were in the case of fossil fuels (DCCEEW, 2025).

Research question

Is nuclear energy more sustainable than Solar Photovoltaic (PV) in terms of cost, reliability and long term waste production?

Cost

LCOE (Levelised Cost of Electricity)

Initiating construction of electrical generation infrastructure is a capital intensive process. For a project to be successful, the money spent during construction and operation, and generation must be lower than the total revenue generated by the infrastructure over its lifespan, and additional profit margins.
Since the sum of costs are recuperated over the lifespan of the infrastructure, comparing them against the sum of energy generated by the plant allows an average cost per unit of energy to be determined. This is known as the LCOE (Levelised Cost of Electricity) for that installation, and is usually measured in dollars per watt hour ().

The CSIRO's GenCost report calculated, and predicted LCOE's for a number of technologies from the years 2024, to 2050, allowing for direct comparison of said technologies (Graham et al., 2024).

Figure 1: Calculated LCOE by technology and category for 2024 and 2030 (AUD) (Graham et al., 2024).

Clearly solar PV demonstrates the lowest LCOE, which is currently 0.16 . The closest nuclear technology to this is large scale nuclear, which is currently priced at 0.40 . While the gap between solar PV and nuclear facilities is predicted to shrink, solar is consistently predicted to be the cheapest option for the foreseeable future.

Capital costs

This is likely due to higher capital, or setup, costs for nuclear options.
The U.S Department of energy's "Capital Cost Estimates For Utility Scale Electricity Generating Plants" further breaks down these capital costs. Financing was estimated to increase capital cost by an additional due to the large magnitude, long term, and high risk loans required for construction
(Leidos Engineering, LLC, 2016). The cost of large scale nuclear in Australia is currently predicted to be in capacity, and is expected to be as low as by 2050 (Graham et al., 2024).

The cost of uranium fuel in America was 0.46 cents/ in 2021. Australia is one of the largest uranium producing countries in the world, so acquiring fuel locally should hypothetically decrease this cost further, however, the cost of fuel is a only minor contributor to LOCE cost in comparison to startup. It is estimated that of LCOE is attributed to capital costs.
(World Nuclear Association, 2020)

The largest capital costs in solar PV systems are the mechanical and electrical systems, and equipment. The procurement and instillation of these components account for of capital costs (Leidos Engineering, LLC, 2016).
Solar PV installations are generally less expensive, and take less time to construct. This translates to lower financing fees, and an overall lower LCOE. The current capital cost of large scale solar PV in Australia is , and is expected to be by 2050 (Graham et al., 2024).

Solar PV's 'fuel' is sunlight, which is a free resource. While land usage scales with capacity, solar PV installations generally are have lower owner costs with respect to the total cost of the installation. Owner costs cover development, property, and other miscellaneous factors (World Nuclear Association, 2024).

Reliability

What is reliability?
Reliability is defined as "The ability of a system or device to carry out it's desired function under predefined circumstances for a certain amount of time" by the Institute of Electrical and Electronics Engineers (Obatola, 2024).
Availability is also a key factor in assessing a systems reliability. It is expressed as a fraction that describes a component or systems operating time in respect to its total lifetime. (Sayed et al., 2019)
Where:

• Mean time to failure is the amount of time the system operates for on average before a failure occurs
• Mean downtime is the time it takes for operations to resume after a failure occurs.

Figure 2: System availability versus system size shows negative trend. P50 (red) and P90 (black) quantile values shown.

"Availability and Performance Loss Factors for U.S. PV Fleet Systems" by Chris Deline et al. considered availability data from large scale solar PV systems up to 10 (10000 ). Figure 2 suggests the median availability (P50) decreases as system capacity grows, however, even as the system capacity surpassed 10 median availability remained at (Deline et al., 2024).

Limitations

"Availability factor of a PV power plant: evaluation based on generation and inverter running periods" by Kumar, N. M., et al. considered inverter uptime in a 1000 plant.

The main contributor to the lowering availability was considered inverter modules, at available in a 1000 system. Often there are many inverters operating in parallel, and the "Plug and play" nature of these components allow repairs to be completed quickly with minimal tools. This is also the case with many other less integral components, which results in relativity high availability for the entire system (Sayed et al., 2019)

Limitations

System availability is affected by all components in the series from the PV modules to the grid. While considering a single component alone, the entire system's availability cannot be properly gauged

Nuclear infrastructure faces many of the same challenges in reliability and longevity as solar PV.
IAEA's Power Reactor Information System (PRIS) is a database of statistics regarding the construction, operation, and capacity of global nuclear energy infrastructure. Extrapolating availability from their public dataset gives a global median of (excluding South Africa) (Iaea.org, 2022).

This is significantly lower than solar PV systems, which seems unlikely due to solar PV relying on occasional daylight to function. However nuclear plants must abide by more stringent safety protocols, therefore more time is spent on both restorative and preventative maintenance as it must be carried out with greater frequency and meticulousness.

For a 1000 reactor, repair timelines range from 9, to 80 days depending on the severity of the fault (Shi & Wang, 2016). This has a significant impact on the overall availability of the system. Furthermore, while solar installations have the ability to degrade 'gracefully', maintaining partial functionality even with the loss of some system components, nuclear plants must maintain full operational capabilities to ensure safety is not compromised.

Furthermore, the output of nuclear facilities is larger than the solar PV infrastructure discussed by a factor of a minimum of 100 times. Considering the decreasing trend observed in availability factor as scale increases, solar PV is hypothesised to have a lower at the same scale as nuclear.

Limitations

Sustainability/Waste Management

Waste generated from electricity generation is generally in the form of solid waste such as aluminium, concrete, and glass, and greenhouse gas emissions (GHG) like .

The waste generated by solar PV systems is approximately 1.7-2 of solid waste per . In Australia, one recycling of these materials is complete, the lifetime emissions 0.046 to 0.059 of per (Barnard, 2025).
This is well below the internationally accepted limits of 50g of (or equivalent) per , about what a tree would absorb in a day (EcoTree, 2022).

Waste generated by nuclear plants is much higher in density. A 1000 reactor creates roughly 10 of waste per , however due to the chaotic and heterogeneous nature of nuclear reasons, the composition of nuclear waste varies.

What remains constant though is the hazard and lifetime of spent fuel. Fission products such as strontium-90, and cesium-137 have half lives of years (World Nuclear Association, 2022). Throughout its lifetime, waste will emit alpha, beta, and gamma, with the latter having the highest potential to cause harm due to its high penetrating power. To minimise potential for irradiation, spent fuel spends 1-50 years in a specialised pool.
Due to the density of the water and the inverse square law, the spent fuel is able to decay and release heat without causing harm before being sealed in a steel and concrete containment vessel. Overall this produces 110 of (equivalent)/.

Limitations

Discussion

Quality of evidence

Extrapolation/Summary of credible findings

Improvements and extensions

Conclusion

References

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Barnard, M. (2025). Solar Panel Waste is Tiny—Coal & Gas Emit Hundreds Of Times Mass Per MWh - CleanTechnica. [online] CleanTechnica. Available at: https://cleantechnica.com/2025/04/19/solar-panel-waste-is-tiny-coal-gas-emit-hundreds-of-times-mass-per-mwh/.

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Potts, P. (2024). Record number of Aussies struggling to pay energy bills amid rising power prices. [online] Sky News. Available at: https://www.skynews.com.au/business/energy/australian-households-continue-to-financially-struggle-to-pay-off-their-energy-bills-as-the-costofliving-crisis-worsens/news-story/854599def1031ade38b3b42247f5452e.

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Deline, C., Muller, M., White, R., Perry, K., Springer, M., Deceglie, M., & Jordan, D. (2024). Availability and performance loss factors for U.S. PV fleet systems (NREL/TP-5K00-88769). National Renewable Energy Laboratory. https://www.nrel.gov/docs/fy24osti/88769.pdf

Graham, P., Hayward, J., & Foster, J. (2024). GenCost 2024-25: Consultation draft. CSIRO.

Kumar, N. M., Dasari, S., & Reddy, J. B. (2018). Availability factor of a PV power plant: Evaluation based on generation and inverter running periods. Energy Procedia, 147, 71–77. https://doi.org/10.1016/j.egypro.2018.07.035

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Shi, J., & Wang, Y. (2016). Reliability prediction and its validation for nuclear power units in service. Frontiers in Energy, 10(3), 425–431. https://doi.org/10.1007/s11708-016-0425-7

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